Dental matrix adjuster and retainer



0a. 22, 1940. M. mm 2,218,774

DENTAL MATRIX ADJUSTER AND RETAINER Filed Feb. 17, 1959 ATTORNEY.

Patented Oct. 22, 1940 UNITED '1 STATES DENTAL MATR PATENT oF IcE2,218,774 is ADJUSTER ANDRETAINER MeyerStrell, Newark, N. J.

Application February 17, 1939, Serial No. 256,871 l Claim. (01. 32-63)plied matrix band around '|a tooth, the tool being self-locking againstrelaxation or loosening of said matrix band after application andadjustment thereof. H

The invention for an object to provide a simple, easily manipul-atab'leand efiicient device for contracting a dental matrix band in snugfitting encircling relation to a tooth and thereupon securely holdingthe samea'giainst displacement from the tooth during the operation offilling a cavity rtherein, obtaining an impression of a cavity therein,or during other operations upon the tooth which are facilitated by thepresence of the matrix band applied thereto.

Other objects of this invention, not at this time more particularlyenumerated, will be understood from the following detailed descriptionof the same.

Illustrative embodiments of this invention are shown in the accompanyingdrawing, in which:

Fig. 1 is a perspective View of one form of the novel dental matrixadjuster and retainer of this invention; Fig. 2 is a top plan view ofthe same, on a somewhat larger scale; Fig. 3 is a vertical crosssection, taken on line 3-3 in Fig. 2; and Fig. 4 is a vertical crosssection, taken on line 4-4 in Fig. 2.

Fig. 5 is a perspective View of the matrix band support with the bandactuating mechanism detached.

Fig. 6 is a top plan view, similar to that of Fig. 2 but showing adifferent way of operatively mounting the matrix band in connection withthe tool. I I

- Fig. '7 is a perspective View of another form of the dental matrixadjuster :andretainer according to this invention; and Fig. 8 is avertical cross section of the samataken on line 8-8 in Fig.7.

Similar characters :of reference are employed in the above describedviews, to indicate corresponding parts. Y

Referring to Figs. 1 to 5 inclusive, the reference character I0indicates a matrix carrier plate comprising a flat strip of sp'ringymetal of suitable length. Formed in connectionwith the forward endportion of said carrier plate I0 is a laterally disposed, outwardlyoflset hollow boss II having a slotted opening "or mouth I2.

The matrix band I3 (which usually consists of a narrow strip of thinpliable metal) is doubled upon itself to form a loop I4, the meeting endportions I5 and I6 :of which are passed rearward-1y through the mouth I2of the boss II, and thence over the rounded shoulder I! at the junctureof said boss with the carrier plate, and

thence along the face of said carrier plate I0.

Mounted in connection withthe rearward end portion of said carrier plateI0 is a housing I8, having :along one side thereof an upstanding flangeI9 with which the carrier plate is connected. Preferably the carrierplate I0 is deta-chaloly coupled to the housing I 8 and its flange I9,and to this end a clamp piece" 20 is provided, the shank 2| of whichextends through an opening 22 in the flange I9. The free end of saidshank 2| is screw-threaded to receive a thumbnut 23. The rearward endportion of said carrier plate I0 is provided with a laterally extend ingnotch 24 which indents one marginal portion of the same. Said rearwardend portion ofthe carrier plate I 0 is engaged between the flange I9 andthe clamp piece 20, with its notch 24 mbracingthe shank'2l of thelatter. When thus disposed the carrier plate is locked in fixed orimmovable relation to the housing I 8 by turning the thumb-nut 23 todraw home the clamppiece 20 into holding engagement with said carrierplate I0. I

' Journaled in said housing I 8, to turn on a vertical axis, a windingbarrel 25, which is thus disposed in upstanding reiation adjacent to thefixed rearward end portion of said carrier plate I0. Afiixed to saidwinding barrel 25, within the interior of the housing I8, is a worm gear26. Journaled in said housing I8, to turn on a horizontal axis, is adrive worm 21 which meshes with said Worm gear 26. Afiixed on anexternal end of said drive worm 2! is a finger piece or knob 28 forrotating the same to thereby transmit rotary motion through said wormgear 26 to said winding barrel 25 in a desired direction. Said windingbarrel 25 is provided with one or more open ended cross slots 29 toreceive the extremities of the end portions I5- -I6 of said matrix bandI 3. In the use of the tool for applying a matrix band I3 in operativerelation to a tooth, the loop I4 is loosely engaged around the tooth,whereupon the operator rotates the'drive worm 21 to impartrotary motionto the winding barrel 25, e. g. in a clockwise direction, therebywinding aroundthe latter the extremities of the matrix band end portionsI5I6, so that the matrix band is drawn outwardly through the slottedopening or mouth I2 of the boss I I, thus con-j to which its loop isapplied; while at the same time providing, exteriorly of the mouth ofthe 1 into patient, visible indication that the matrix band loop hasattained snugly embracing operative relation to said tooth. Owing to thefact that the v rive worm and worm gear transmission is self-lockingagainst back-lash and against reverse rortlation of the Winding barrelunder the pull of the tautened matrix band, the latter is firmly heldagainst relaxation.

It will be obvious that the tool may be used and applied to selectedteeth at either side of the jaws, and in either the upper or lower jawregions, merely by turning the tool to such position that the boss H isdisposed to: impinge the particular tooth to which it is desired toapply the matrix band.

In some cases it may be desired to remove the carrier plate from theactuating mechanism carried by the housing l8, and after the matrix bandis operatively applied to a tooth. In such case, the end portions l5-|6of the matrix band are secured to the carrier plate II] by springgripping clips 30 of suitable kind (see Fig. 5). After the matrix band.is thus secured to the carrier plate l0 against displacement, thewinding barrel 25 is reversely rotated to disengage the extremities ofthe matrix band, therefrom, whereupon the thumb-nut 23 is loosened to inturn loosen the clamp piece 20 so that the housing l8 and carrier plateIt) may be separated and detached one from the other.

The novel tool, in the form thereof above described may besatisfactorily used with short lengths of matrix band material. This isshown in Fig. 6, wherein the matrix band I3 is formed a tooth encirclingloop M and passed through the openin or mouth l2 of the boss H in suchmanner as to provide an inwardly disposed short end portion [5 and anoutwardly disposed long end portion It. The extremity of the long endportion i6 is engaged with the winding barrel 25, and by rotating thelatter is drawn taut. The tautened long end portion l6 will press andhold the short end portion I5 into snubbed relation to the shoulder ll,thus preventing longitudinal displacement. thereof, and consequentlymaintaining the loop of the matrix band in tight encircling andembracing relation to the tooth to which it is applied.

In Figs. 7 and 8 there is shown a modified form of the novel matrix bandadjusting and retaining device according to this invention. Thismodified form of the device comprises a housing mem ber 3| having afront wall portion 32 provided with a vertical slotted opening or mouth33 extending therethrough into communication with a space intermediatethe housing body and a top bracket 34 spaced thereabove and springingfrom said wall portion 32. Journaled in said housing 3| and bracket 34,to extend vertically therebetween and behind said wall portion 32 is awinding barrel 35. Afiixed to the winding barrel 35, within the interiorof the housing 3!, is a worm gear 36. Journaled in said housing, to turnon a horizontal axis, is a drive worm 3'! which meshes with said wormgear 36. Connected with said drive worm 31, to extend axially therefromis a long shaft or stem Men the free end of which is affixed a fingerpiece or knob 39 for rotating the same and said drive worm. The matrixband, as used With the above described modified form of adjusting andretaining means, is doubled uponitself to form a loop 40, the meetingend portions 4i and 42 of which are passed through the opening or mouth33, and then engaged through the cross slot 43 of said winding barrel35. In the use of this modified form of matrix band adjusting andretaining device, the loop 40 of the matrix band is loosely engagedaround a tooth, whereupon the operator rotates the drive worm 31 to inturn rotate the winding barrel so as to wind onto the same the endportions 41-42 of the matrix band, thereby tightly contracting the loopin tight and snug fitting encircling engagement with and around thetooth. As in the first described construction, so in the last describedmodified construction, the drive worm and worm gear transmission is selflocking against back-lash and against reverse rotation of the windingbarrel with consequent undesired relaxation or loosening of the loop ofsaid matrix band relative to the tooth to which it isapplied.

From the above description it will be apparent that this inventionprovides a very simple, efficient and easily and quickly manipulateddevice for adjusting and retaining a dental matrix band in snug fittingrelation to a tooth in connection with which it is desired to be usedfor purposes well known to the dental practitioner.

I am aware that various changes could be made in the devices embodyingthis invention, and that apparently widely different constructionsthere-- of could be made without departing from the scope thereof asdefined in. the following claims. It is therefore intended that allmatter contained in the foregoing description or shown in theaccompanying drawing shall be interpreted as illustrative and not in alimiting sense.

I claim:

A. dental matrix forming means comprising, a housing member having anexternally projecting upstanding cross-slotted winding barrel journaledtherein and'a worm and gear means for actuating said barrel, saidhousingmemberhaving an upstanding flange laterally offset parallel tosaid barrel, a clamp means carried by said flange, an elongated carrierplate of springy material having means at its rearward end portionengageable with said clamp means to detachably anchor the same to saidflange for free forward extension from said housing member, said carrierplate having a laterally projected slotted boss at its forward free endportion, a matrix loop band having its closed together end portionsextending rearwardly through said slotted boss and thence back alongsaid carrier plate into operative engagement with said winding barrel,rotation of said winding barrel being operative to tightly contractsaidloop band around a tooth encircled thereby, said carrier plate beingadapted to bow slightly under the tension of said tightened loop band tothereby provide, exteriorly of the mouth of the patient, visibleindication that said loop band has attained snugly embracing relation tothe tooth encircled thereby, detachable means for holding the endportions of the tightened loop band in secured relation to the carrierplate, whereby, whenv the extremities of said loop band are releasedfrom said winding barrel, the latter with its supporting housing memberand, actuating worm and gear means may be removed from said carrierplate upon release of said clamp means.

MEYER STRELL.

